package com.hewl.exer;

import org.junit.Test;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

/**
 * @author wen
 * @date 2021-07-14
 */
public class PicTest {
    //图片的加密
    @Test
    public void test1(){
        FileInputStream fis = null;
        FileOutputStream fos = null;
        try {
            fis = new FileInputStream("超越.jpg");
            fos = new FileOutputStream("超越secret.jpg");

            byte[] buffer = new byte[20];
            int len;
            while((len = fis.read(buffer))!=-1){
                //字节数组进行修改
                //错误的写法
    //            for (byte b : buffer) {
    //                b = (byte) (b ^ 5);
    //            }
                //正确的写法
                for (int i = 0; i < len; i++) {
                    buffer[i] = (byte) (buffer[i] ^ 5);
                }
                fos.write(buffer,0,len);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(fos != null){
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(fis != null){
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }
    //图片的解密
    @Test
    public void test2(){
        FileInputStream fis = null;
        FileOutputStream fos = null;
        try {
            fis = new FileInputStream("超越secret.jpg");
            fos = new FileOutputStream("超越3.jpg");

            byte[] buffer = new byte[20];
            int len;
            while((len = fis.read(buffer))!=-1){
                //字节数组进行修改
                //错误的写法
                //            for (byte b : buffer) {
                //                b = (byte) (b ^ 5);
                //            }
                //正确的写法
                for (int i = 0; i < len; i++) {
                    buffer[i] = (byte) (buffer[i] ^ 5);
                }
                fos.write(buffer,0,len);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(fos != null){
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(fis != null){
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }
}
